September 9, 2021

New ultrasound tool will make orthodontic imaging safer

PhD student Kim Cuong Nguyen

Photo submitted by Nguyen.

More than four million people in Canada and the U.S. are receiving orthodontic care, most of them older children and teenagers. One of the treatments most will undergo is forced movement of their teeth to correct crowding.

A University of Alberta PhD student and her supervisors are working on an important project to find a safe imaging tool to allow orthodontists to assess the level of bone support in the mouth and track the progress of the treatments.

There is currently no viable way to image the bone on the outside aspect of the teeth without exposing a child or adolescent to excessive radiation, says Paul Major, chair of the U of A’s School of Dentistry. The collaborators are working on a high-frequency ultrasound tool to do orthodontic imaging in a safe and efficient way.

WCHRI is supporting the work being done on the project by Kim Cuong Nguyen, who is nearing the end of an interdisciplinary PhD in Radiology and Diagnostic Imaging and Biomedical Engineering. Her research is supervised by Major and Lawrence Le, a professor in the Department of Radiology & Diagnostic Imaging. They began the study more than five years ago.

“When Dr. Le told me about this project, about applying ultrasound in dentistry, I was very excited,” says Nguyen, a Killam Laureate. “It’s very new—not many groups in the world are working on this and no one has done clinical trials. I am very grateful to be part of this project.”

Traditional dental x-rays are two-dimensional and not capable of imaging bone on the outside of the tooth, says Major. A technology called Cone Beam Computed Tomography (CBCT) is a three-dimensional scan that could image the bone but would expose young patients to far too much radiation. Excessive radiation increases the risk of cancer, especially in children, who still have growing organs.

Ultrasound imaging is radiation-free, less costly and non-invasive. But traditional medical ultrasound tools are too large to use in the mouth and have not provided high enough resolution.

The collaborators, who have formed a spin-off company called DenSonics Imaging Inc., have developed a high-resolution ultrasound device that is small, portable and produces good images of the bone. They have funding from various agencies, including the National Research Council’s Canada Industrial Research Assistance Program, and hope to start commercialization of their prototype in the near future.

Nguyen has been the “jack-of-all-trades on the project,” says Le. She has been involved in a clinical trial involving 30 adolescent patients in the School of Dentistry’s orthodontic clinic. And she has been working on machine-learning algorithms and software tools that will help clinicians interpret ultrasound images.

Dentists are not trained to understand ultrasound images, which are complex to interpret, says Major. Nguyen’s work in this area “is a critical step in getting this out into widespread use,” he adds.

Both Major and Le praised Nguyen for her contributions to the project. “I’ve worked with a lot of students over the years and I think KC [Nguyen’s nickname] has done an astounding job,” says Major. “She’s very good at working her way through the problems. It’s very challenging to work in interdisciplinary spaces like this.”

Kim Cuong Nguyen is a PhD student in the departments of radiology and diagnostic imaging and biomedical engineering and is co-supervised by Lawrence Le, Paul Major and Edmond Lou. Her graduate studentship is funded by the Stollery Children’s Hospital Foundation and the Alberta Women’s Health Foundation through WCHRI.

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